scholarly journals A Lymphoid Organ Specific Anti-Lipopolysaccharide Factor from Litopenaeus vannamei Exhibits Strong Antimicrobial Activities

Marine Drugs ◽  
2021 ◽  
Vol 19 (5) ◽  
pp. 250
Author(s):  
Mingzhe Sun ◽  
Shihao Li ◽  
Xinjia Lv ◽  
Jianhai Xiang ◽  
Yuanan Lu ◽  
...  
Keyword(s):  
Antimicrobial Peptides ◽  
Litopenaeus Vannamei ◽  
Fenneropenaeus Chinensis ◽  
Antibacterial Activities ◽  
Antimicrobial Activities ◽  
Lymphoid Organ ◽  
Shrimp Species ◽  
New Findings ◽  
New Research

Different shrimp species are known to possess apparent distinct resistance to different pathogens in aquaculture. However, the molecular mechanism underlying this finding still remains unknown. One kind of important antimicrobial peptides, anti-lipopolysaccharide factors (ALF), exhibit broad-spectrum antimicrobial activities. Here, we reported a newly identified ALF from the shrimp Litopenaeus vannamei and compared the immune function with its counterpart in the shrimp Fenneropenaeus chinensis. The ALF, designated as LvALF8, was specifically expressed in the lymphoid organ of L. vannamei. The expression level of LvALF8 was apparently changed after white spot syndrome virus (WSSV) or Vibrio parahaemolyticus challenges. The synthetic LBD peptide of LvALF8 (LvALF8-LBD) showed strong antibacterial activities against most tested Gram-negative and Gram-positive bacteria. LvALF8-LBD could also inhibit the in vivo propagation of WSSV similar as FcALF8-LBD, the LBD of LvALF8 counterpart in F. chinensis. However, LvALF8-LBD and FcALF8-LBD exhibited apparently different antibacterial activity against V. parahaemolyticus, the main pathogen causing acute hepatopancreatic necrosis disease (AHPND) of affected shrimp. A structural analysis showed that the positive net charge and amphipathicity characteristics of LvALF8-LBD peptide were speculated as two important components for its enhanced antimicrobial activity compared to those of FcALF8-LBD. These new findings may not only provide some evidence to explain the distinct disease resistance among different shrimp species, but also lay out new research ground for the testing and development of LBD-originated antimicrobial peptides to control of shrimp diseases.

scholarly journals Identification of Synthetic Host Defense Peptide Mimics That Exert Dual Antimicrobial and Anti-Inflammatory Activities

2012 ◽  
Vol 19 (11) ◽  
pp. 1784-1791 ◽  
Author(s):  
Abhigyan Som ◽  
Nicolás Navasa ◽  
Avital Percher ◽  
Richard W. Scott ◽  
Gregory N. Tew ◽  
...  
Keyword(s):  
Antimicrobial Peptides ◽  
Lipoteichoic Acid ◽  
Antibacterial Activities ◽  
Innate Immune Responses ◽  
Content Type ◽  
Host Defense Peptide ◽  
Anti Inflammatory ◽  
Molecular Patterns

ABSTRACTA group of synthetic antimicrobial oligomers, inspired by naturally occurring antimicrobial peptides, were analyzed for the ability to modulate innate immune responses to Toll-like receptor (TLR) ligands. These synthetic mimics of antimicrobial peptides (SMAMPs) specifically reduced cytokine production in response toStaphylococcus aureusand theS. aureuscomponent lipoteichoic acid (LTA), a TLR2 agonist. Anti-inflammatory SMAMPs prevented the induction of tumor necrosis factor (TNF), interleukin 6 (IL-6), and IL-10 in response toS. aureusor LTA, but no other TLR2 ligands. We show that these SMAMPs bind specifically to LTAin vitroand prevent its interaction with TLR2. Importantly, the SMAMP greatly reduced the induction of TNF and IL-6in vivoin mice acutely infected withS. aureuswhile simultaneously reducing bacterial loads dramatically (4 log10). Thus, these SMAMPs can eliminate the damage induced by pathogen-associated molecular patterns (PAMPs) while simultaneously eliminating infectionin vivo. They are the first known SMAMPs to demonstrate anti-inflammatory and antibacterial activitiesin vivo.

Induction of antimicrobial peptides from Rana dybowskii under Rana grylio virus stress, and bioactivity analysis

2012 ◽  
Vol 58 (7) ◽  
pp. 848-855 ◽  
Author(s):  
Shu-Jing Yang ◽  
Xiang-Hong Xiao ◽  
Yi-Gang Xu ◽  
Dan-Dan Li ◽  
Long-Hui Chai ◽  
...  
Keyword(s):  
Antimicrobial Peptides ◽  
Antimicrobial Activities ◽  
The Other ◽  
Degenerate Primers ◽  
Cdna Sequences ◽  
Gram Positive Bacteria ◽  
Pathogen Invasion ◽  
Peptide Precursors ◽  
Rana Dybowskii

The skin glands of Ranidae are a rich source of antimicrobial peptides. In this study, the genomic RNA of Rana dybowskii was extracted from its skin while under Rana grylio virus stress. Five new cDNA sequences encoding 5 mature peptides, Ranatuerin-2YJ (GLMDIFKVAVNKLLAAGMNKPRCKAAHC), Dybowskin-YJb (IIPLPLGYFAKKP), Dybowskin-YJa (IIPLPLGYFAKKKKKKDPVPLDQ), Temperin-YJa (VLPLLETCSMTCWENNQTFGK), and Temperin-YJb (VLPLVGNLLNDLLGK), were obtained by reverse transcription polymerase chain reaction with a pair of degenerate primers designed according to the conserved terminal sequences of cDNA encoding antimicrobial peptide precursors of genus Rana. The antimicrobial activities of the peptides were analyzed, and the results demonstrated that all these peptides showed a significant anti-Rana grylio virus activity, and the virus was gradually cleared with the increase in gene expression. Among the 5 peptides obtained in this work, Ranatuerin-2YJ also showed a broad-spectrum anti-Gram-positive bacteria and anti-Gram-negative bacteria activity with a minimal inhibitory concentration of 22.5 µg/mL and 7.64% hemolysis activity, both of which were significantly lower (p < 0.05) than that of the other peptides. Moreover, Ranatuerin-2YJ was widely distributed in the skin, liver, spleen, and blood of R. dybowskii, while the other 4 peptides could only be cloned from the skin, indicating that the Ranatuerin-2YJ in vivo plays an important role in the protection against pathogen invasion.

scholarly journals Invitro Antimicrobial Activities of Mitracarpus scaber Against Some Common Bacteria of Aquatic Origin

2021 ◽  
Vol 32 (3) ◽  
pp. 119
Author(s):  
Abdullateef Abiodun Ajadi ◽  
Benjamin Emikpe ◽  
Ahmed Akeem
Keyword(s):  
Antimicrobial Properties ◽  
Ethanolic Extract ◽  
Antibacterial Activities ◽  
Antimicrobial Activities ◽  
Phytochemical Analysis ◽  
Ethanolic Extracts ◽  
Zones Of Inhibition ◽  
Mitracarpus Scaber

Some plants have been reported to be of medicinal values and reserve some antimicrobial properties. One of such plants is Mitracarpus scaber and its effect on bacterial growth is evaluated. The study aimed at evaluating the phytochemical analyses and antimicrobial potentials of Mitracarpus scaber against aquatic bacteria including Aeromonas, Bacillus, Vibrio and Staphylococcus Spp. Leaves of Mitracarpus scaber were collected, washed and air dried and phytochemical analysis and antimicrobial investigation of ethanolic and aqueous extracts of the leaves were carried out against a panel of bacteria isolated from diseased catfish from various farms. The phytoconstituents detected include saponins, tannins, flavonoids, tarpenoids, steroids, anthraquinones and alkaloids in both aqueous and ethanolic extracts. Both aqueous and ethanolic extracts of M. scaber showed varying degree of antibacterial activities but ethanolic extract showed a higher activity against the pathogens tested. The ethanolic extract had zones of inhibition similar to that of standard antibiotics (enrofloxacin) across all tested microbes.  The lowest minimum inhibitory concentration of ethanolic extract of M. scaber was against Bacillus sp with 10mg/ml while the highest was 85mg/ml against Staphylococcus species. The results of the assays showed promising evidences that M. scaber is a potential antibacterial agent against aquatic microbes.  However, further studies are recommended to fractionate its constituents and determine the in vitro and in vivo anti-microbial activities and the exact mechanism of action of the constituents.

Copper(II) mixed-ligand complexes containing 1, 10-phenanthroline, adenine and thymine: Synthesis, characterization and antibacterial activities

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Copper Complexes ◽  
Antimicrobial Agents ◽  
Conductivity Measurement ◽  
Antibacterial Activities ◽  
Antimicrobial Activities ◽  
Bacterial Strains ◽  
E Coli ◽  
In Vivo Cytotoxicity

New copper complexes, [Cu(phen)2(Thy)]2Cl and [Cu(phen)2(Ad)]2Cl (phen = 1,10-phenantroline, Ad (Adenine, a purine nucleobase) and Thy (Thymine, a pyrimidine nucleobase)), were synthesized and characterized by atomic absorption spectroscopy (AAS), conductivity measurement, UV-visible and infrared (IR) techniques. The complexes were tested for their antimicrobial activity against two gram positive and two gram negative bacterial strains. The results of in vitro antimicrobial activities were compared with the commercially available antimicrobial agents (ciprofloxacin and chloramphenicol). This comparative study has demonstrated that [Cu(phen)2(Thy)]2Cl inhibited the growth of methicillin resistant Staphylococcus aureous (MRSA), Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumonia) better than chloramphenicol by 11.25%, 19.41% and 25.35%, respectively. It also showed better activities than ciprofloxacine on MRSA and K. pneumoniae by 2.50% and 12.13%, respectively. Similarly, [Cu(phen)2(Ad)]2Cl demonstrated better inhibitions than chloramphenicol against MRSA, E. coli and K. pneumoniae by 11.24%, 2.48% and 9.06%, respectively. Therefore, after in vivo cytotoxicity investigations, these complexes could be considered as potential antimicrobial agents.

scholarly journals Human Antimicrobial Peptides as Therapeutics for Viral Infections

Viruses ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 704 ◽  
Author(s):  
Aslaa Ahmed ◽  
Gavriella Siman-Tov ◽  
Grant Hall ◽  
Nishank Bhalla ◽  
Aarthi Narayanan
Keyword(s):  
Antimicrobial Peptides ◽  
Viral Infections ◽  
Therapeutic Potential ◽  
Antimicrobial Activities ◽  
Viral Pathogens ◽  
Multiple Organs ◽  
Pathogen Entry ◽  
Primary Focus ◽  
Therapeutic Tools

Successful in vivo infection following pathogen entry requires the evasion and subversion of multiple immunological barriers. Antimicrobial peptides (AMPs) are one of the first immune pathways upregulated during infection by multiple pathogens, in multiple organs in vivo. In humans, there are many classes of AMPs exhibiting broad antimicrobial activities, with defensins and the human cathelicidin LL-37 being the best studied examples. Whereas historically the efficacy and therapeutic potential of AMPs against bacterial infection has been the primary focus of research, recent studies have begun to elucidate the antiviral properties of AMPs as well as their role in regulation of inflammation and chemoattraction. AMPs as therapeutic tools seem especially promising against emerging infectious viral pathogens for which no approved vaccines or treatments are currently available, such as dengue virus (DENV) and Zika virus (ZIKV). In this review, we summarize recent studies elucidating the efficacy and diverse mechanisms of action of various classes of AMPs against multiple viral pathogens, as well as the potential use of human AMPs in novel antiviral therapeutic strategies.

scholarly journals In VitroandIn VivoActivities of Antimicrobial Peptides Developed Using an Amino Acid-Based Activity Prediction Method

2014 ◽  
Vol 58 (9) ◽  
pp. 5342-5349 ◽  
Author(s):  
Xiaozhe Wu ◽  
Zhenling Wang ◽  
Xiaolu Li ◽  
Yingzi Fan ◽  
Gu He ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Amino Acid ◽  
Antimicrobial Peptides ◽  
Bacterial Load ◽  
Prediction Method ◽  
Multidrug Resistant ◽  
Antimicrobial Activities ◽  
Bacterial Strains ◽  
Content Type

ABSTRACTTo design and discover new antimicrobial peptides (AMPs) with high levels of antimicrobial activity, a number of machine-learning methods and prediction methods have been developed. Here, we present a new prediction method that can identify novel AMPs that are highly similar in sequence to known peptides but offer improved antimicrobial activity along with lower host cytotoxicity. Using previously generated AMP amino acid substitution data, we developed an amino acid activity contribution matrix that contained an activity contribution value for each amino acid in each position of the model peptide. A series of AMPs were designed with this method. After evaluating the antimicrobial activities of these novel AMPs against both Gram-positive and Gram-negative bacterial strains, DP7 was chosen for further analysis. Compared to the parent peptide HH2, this novel AMP showed broad-spectrum, improved antimicrobial activity, and in a cytotoxicity assay it showed lower toxicity against human cells. Thein vivoantimicrobial activity of DP7 was tested in aStaphylococcus aureusinfection murine model. When inoculated and treated via intraperitoneal injection, DP7 reduced the bacterial load in the peritoneal lavage solution. Electron microscope imaging and the results indicated disruption of theS. aureusouter membrane by DP7. Our new prediction method can therefore be employed to identify AMPs possessing minor amino acid differences with improved antimicrobial activities, potentially increasing the therapeutic agents available to combat multidrug-resistant infections.

Recent Advances in the Development of Antimicrobial Peptides (AMPs): Attempts for Sustainable Medicine?

2018 ◽  
Vol 25 (21) ◽  
pp. 2503-2519 ◽  
Author(s):  
Anne Kokel ◽  
Marianna Torok
Keyword(s):  
Side Effects ◽  
Antimicrobial Peptides ◽  
Potential Drug ◽  
Green Technologies ◽  
Specific Antibodies ◽  
Structural Modifications ◽  
Drug Candidates ◽  
Induce Resistance ◽  
Conventional Antibiotics

Background: Since the first isolation of antimicrobial peptides (AMPs) they have attracted extensive interest in medicinal chemistry. However, only a few AMP-based drugs are currently available on the market. Despite their effectiveness, biodegradability, and versatile mode of action that is less likely to induce resistance compared to conventional antibiotics, AMPs suffer from major issues that need to be addressed to broaden their use. Notably, AMPs can lack selectivity leading to side effects and cytotoxicity, and also exhibit in vivo instability. Several strategies are being actively considered to overcome the limitations that restrain the success of AMPs. Methods: In the current work, recent strategies reported for improving AMPs in the context of drug design and delivery were surveyed, and also their possible impact on patients and the environment was assessed. Results: As a major advantage AMPs possess an easily tunable skeleton offering opportunities to improve their properties. Strategic structural modifications and the beneficial properties of cyclic or branched AMPs in term of stability have been reported. The conjugation of AMPs with nanoparticles has also been explored to increase their in vivo stability. Other techniques such as the coupling of AMPs with specific antibodies aim to increase the selectivity of the potential drug towards the target. These strategies were evaluated for their effect on the environment highlighting green technologies. Conclusion: Although further research is needed taking into account both environmental and human health consequences of novel AMPs, several of these compounds are promising drug candidates for use in sustainable medicine.

Antimicrobial peptides for the treatment of pulmonary tuberculosis, allies or foes?

2018 ◽  
Vol 24 (10) ◽  
pp. 1138-1147
Author(s):  
Bruno Rivas-Santiago ◽  
Flor Torres-Juarez
Keyword(s):  
Pulmonary Tuberculosis ◽  
Antimicrobial Peptides ◽  
Experimental Models ◽  
New Drugs ◽  
World Health ◽  
Public Health Issue ◽  
Health Organization ◽  
Drug Resistant Strains

Tuberculosis is an ancient disease that has become a serious public health issue in recent years, although increasing incidence has been controlled, deaths caused by Mycobacterium tuberculosis have been accentuated due to the emerging of multi-drug resistant strains and the comorbidity with diabetes mellitus and HIV. This situation is threatening the goals of World Health Organization (WHO) to eradicate tuberculosis in 2035. WHO has called for the creation of new drugs as an alternative for the treatment of pulmonary tuberculosis, among the plausible molecules that can be used are the Antimicrobial Peptides (AMPs). These peptides have demonstrated remarkable efficacy to kill mycobacteria in vitro and in vivo in experimental models, nevertheless, these peptides not only have antimicrobial activity but also have a wide variety of functions such as angiogenesis, wound healing, immunomodulation and other well-described roles into the human physiology. Therapeutic strategies for tuberculosis using AMPs must be well thought prior to their clinical use; evaluating comorbidities, family history and risk factors to other diseases, since the wide function of AMPs, they could lead to collateral undesirable effects.

Punica granatum as a Source of Natural Antioxidant and Antimicrobial Agent; a Comprehensive Review on Related Investigations

2020 ◽  
Vol 17 ◽  
Author(s):  
Atefeh Jalali ◽  
Mohammadreza Kiafar ◽  
Masih Seddigh ◽  
Mohammad M. Zarshenas
Keyword(s):  
Antioxidant Activities ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Natural Antioxidants ◽  
Punica Granatum ◽  
Antimicrobial Activities ◽  
Natural Antioxidant ◽  
Antiviral Activities ◽  
Natural Foods

Background: The consumption of natural antioxidants is increasing due to the demand and tendency to natural foods. Punica granatum L. [Punicaceae] is a fruit with various bioactive ingredients. The effectiveness of this plant has been proved against various disorders such as hyperglycemia, hyperlipidemia, blood coagulation, infections, cancer, and dentistry. Among them, there are numerous researches on antimicrobial and antioxidant properties. Subsequently, the present study aimed to compile a review of those properties to outline this herb as a possible natural antioxidant and preservative. Methods: Synchronically, keywords "Punica granatum" with antimicrobial, or antibacterial, antifungal, antiviral, antioxidant and radical scavenging were searched through "Scopus" database up to 31st September 2019. Papers focusing on agriculture, genetics, chemistry, and environmental sciences were excluded and also related papers were collected. Results: Among 201 papers focusing on related activities, 111 papers have dealt with antioxidant activities focusing based on DPPH assay, 59 with antibacterial, on both gram+ and gram- bacteria, 24 with antifungal effects, mostly on Aspergillus niger and Candida albicans, and 7 papers with antiviral activities. There were about 50 papers focusing on in-vivo antioxidant activities of this plant. Conclusion: Taken together, botanical parts of P. granatum have possessed notable radical scavenging and antimicrobial activities that with these properties, this plant can be introduced as a natural safe source of preservative and antioxidant. Accordingly, P. granatum can be applied as excipient with the aforementioned properties in the pharmaceutical and food industries.

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